The controlled coating of substrates with a film polymer by vapor deposition is disclosed in U.S. Pat. No. 4,495,889 to Riley. The process disclosed in this patent utilizes controlled vapor phase deposition of a di-p-xylylene dimer onto a substrate. The dimer is created by first vaporizing a cyclic dimer into a vapor phase and then cleaving the vapor dimer into reactive diradicals. These are conducted into a deposition chamber where a substrate or workpiece is coated. The disclosure of the '889 prior art patent is incorporated herein by reference.
The polymeric coating process of the aforementioned patent is operated in stages that can take a variable amount of time to accomplish. During a coating run, the pressure and temperature of subsystems within the coating system are monitored to achieve a coating in a minimum amount of time. Critical parameters for controlling the process have been obtained through long experience with such a system. A skilled operator familiar with the system can monitor these critical parameters and based upon his or her past experience can accurately judge when the coating process has been completed. Since a typical polymer coating process can take hours, however, it is desirable that less skilled personnel be assigned the task of monitoring these parameters without requiring the presence of one intimately familiar with the coating system.
A less experienced user cannot rely upon his or her experience in past coating runs and, must instead be given parameters indicative of the performance of the process. By monitoring these parameters, the acceptability of the coating can be determined.
The apparatus of the '889 invention includes a computer having a pressure monitor and a heater control. One task the computer of the prior art coating system performs is to monitor the monomer vapor pressure leading to the deposition chamber and control the vaporization temperature to finish a coating run in a minimal amount of time. Experience with this prior art system has indicated that while this procedure is a successful and important use of the computer a display of more information by the computer could be helpful in assessing coating operations and could be used to train and familiarize new users with the coating system.